1. Field of the Invention
The present invention relates to a contour configuration machining system of an interactive numerical control apparatus, and more specifically, to a contour configuration machining system by which a cutting direction can be arbitrarily changed.
2. Description of the Related Art
Interactive numerical control apparatuses are widely used to control various machine tools, because an operator can easily create programs without the need for taking a language protocol, NC tape format and the like of an automatic programming into consideration.
For example, when a machining operation is carried out by a lathe, an interactive type input of configuration data by an operator enables a program to be created by automatically calculating intersect and contact points of a contour configuration and like. Interactive input can be used to produce a program for a machining operation beginning at the start point of a first configuration data and carried out along the required contour configuration.
Nevertheless, some of the tools used for a lathe produce cutting performances in accordance with the cutting directions thereof. When such a tool is used in a conventional cutting system, the machining operation is not always carried out in an optimum cutting direction of the tool for all portions of a workpiece being machined. This results when the machining operation is carried out along a configuration composed of a series of contours. As a result, the machining efficiency is lowered and the tool life is shortened.